Irritation of the facial nerve
A permanent irritation of the facial nerve can trigger a facial spasm (so-called spasm hemifacialis). In this case, pressure is often exerted on the nerve by a blood vessel, resulting in damage to the insulating layer of the facial nerve. The excitability of the nerve is then increased and a state of permanent irritation occurs. This manifests itself in a one-sided cramping of the facial muscles, which usually lasts less than 1 second. The cause of the irritation can be an aneurysm, i.e. the lateral bulge of a blood vessel, or more rarely brain tumors or multiple sclerosis.
Pain
Pain caused by damage to the facial nerve is often a harbinger of facial palsy. Those affected usually complain of pain in the area behind the ear two to three days before the onset of hemiplegia. The lower jaw area can also be affected.
If very severe pain occurs, an attempt can be made to treat it with ASA (Aspirin®), for example. In so-called facial paresis or facial paralysis, one side of the facial muscles is paralyzed. Which side is affected depends on the cause of the paralysis and the location of the nerve damage.
A distinction is made between central and peripheral facial paresis. In central paresis, the damage to the nerve lies in the brain and can be triggered by a stroke or a brain tumor. The nerve itself is therefore not damaged.
In peripheral facial nerve palsy, the damage affects the facial nerve itself. This can have various causes. Facial nerve palsy manifests itself in unilateral incomplete closure of the eyelid, drooping corner of the mouth, impaired sense of taste, hypersensitivity to loud noises and reduced tearing and salivation.
Behind the ear the sensation is disturbed in a small area.In peripheral facial paralysis, unlike central paralysis, frowning is not possible. Because of the paralyzed facial muscles, there are often difficulties in word formation. As a rule, the hemiplegia of the face disappears again with the right treatment.
After six months at the latest, there should be no more symptoms. Permanent facial asymmetries are only observed in a few cases, whereas in many people inconspicuous co-movements of the facial muscles remain when talking. Circulatory disorders of the nerve are often responsible for this.
Nerve damage can also be caused by cranial injuries. But also middle ear inflammations can pass over to the facialis nerve due to the spatial proximity. Furthermore, infections with certain bacteria or viruses can cause an inflammation of the nerve and lead to peripheral facial nerve palsy.
These include the bacterial species Borrelia (transmissible by ticks) and the Varicella zoster virus (responsible for chickenpox, shingles and zoster oticus). Facial paresis can also occur in the context of meningitis or in connection with diabetes mellitus. In most cases, however, no cause can be found.
In this case one speaks of an idiopathic facial nerve palsy. The diagnosis is usually made by the clear half-sided paralysis symptoms. In order to find out the extent and cause, various tests and examinations can be carried out.
For example, a taste test can provide information about the location of the nerve damage. In some cases, X-rays, CT or MRI images of the head must be taken to identify or rule out any bony damage to the skull or brain tumors. Depending on the cause, the symptoms can be improved by various therapeutic approaches.
Antibiotics for bacteria as the cause, or acyclovir for proven Varicella zoster virus, are used as treatment. Surgery may be necessary for existing cranial injuries. In addition, physiotherapeutic exercises of the facial muscles are often necessary.
Patients in whom the cause is unclear are treated with so-called corticosteroids, such as cortisone. This treatment can be done on an outpatient basis. The eye is often at risk of drying out due to incomplete eyelid closure. It may therefore be necessary to keep the eye moist with eye ointment or eye drops.
